Sound speed in pure water. Marczak equation

Mathematical definition

$$\boxed{C\left( T \right) = {k_0} + {k_1}T + {k_2}{T^2} + {k_3}{T^3} + {k_4}{T^4} + {k_5}{T^5}}$$

Notation Description Units Limits
$C$ sound speed $\text{m/s}$
$T$ temperature $^{\circ}\text{C}$ $0 < T < 95$
Coefficient Value
$k_{0}$ $+1.402385 \times 10^{3}$
$k_{1}$ $+5.038813$
$k_{2}$ $-5.799136 \times 10^{-2}$
$k_{3}$ $+3.287156 \times 10^{-4}$
$k_{4}$ $-1.398845 \times 10^{-6}$
$k_{5}$ $+2.787860 \times 10^{-9}$

Octave/Matlab implementation

function C = sound_speed_water_marczak(T)
% Inputs
%    T: temperature \ degree Celsius \ 0 < T < 95
% Outputs
%    C: speed of sound in pure water \ m/s

    k0 = +1.402385e+3;
    k1 = +5.038813e+0;
    k2 = -5.799136e-2;
    k3 = +3.287156e-4;
    k4 = -1.398845e-6;
    k5 = +2.787860e-9;

    C = k0*(T.^0) + k1*(T.^1) + k2*(T.^2) ...
        + k3*(T.^3) + k4*(T.^4) + k5*(T.^5);   
end

Computational examples

References

  1. Marczak, Wojciech, "Water as a standard in the measurements of speed of sound in liquids", 1997